You can do more than just remember your old Commodore 64, as there are plans to bring it back by the end of the year, just in time for Christmas.
You might have seen our article on Haiku, an open source implementation of BeOS. It’s not the only open source re-implementation of a classic computer OS. Icaros is a reimplementation of the classic Amiga OS for PCs. It’s based on AROS (the Amiga Research Operating System), but is available in a ready-to-run live version.